// custom_type.hpp - v1.0
/*
 *  Copyright (c) 2007 Leigh Johnston.
 *
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *
 *     * Neither the name of Leigh Johnston nor the names of any
 *       other contributors to this software may be used to endorse or
 *       promote products derived from this software without specific prior
 *       written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 *  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 *  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 *  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 *  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 *  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#pragma once

#include "neolib.hpp"
#include <any>
#include <sstream>
#include <optional>
#include "reference_counted.hpp"
#include "string.hpp"
#include "type_traits.hpp"
#include "i_custom_type.hpp"

namespace neolib
{
    namespace detail
    {
        template <bool>
        struct to_string
        {
            template <typename T>
            i_string* operator()(const T& aValue)
            {
                std::ostringstream oss;
                oss << aValue;
                return new string(oss.str());
            }
        };
        template <>
        struct to_string<false>
        {
            template <typename T>
            i_string* operator()(const T& aValue)
            {
                return new string();
            }
        };
    }

    template <typename AbstractType, typename ConcreteType>
    class custom_type : public reference_counted<i_custom_type>
    {
    public:
        struct type_mismatch : std::logic_error { type_mismatch() : std::logic_error("neolib::custom_type::type_mismatch") {} };
    private:
        typedef std::optional<ConcreteType> container_type;
    public:
        custom_type(const string& aName) :
            iName(aName) {}
        custom_type(const string& aName, const AbstractType& aInstance) :
            iName(aName), iInstance(aInstance) {}
        custom_type(const i_custom_type& aOther) :
            iName(aOther.name()), iInstance(aOther.instance_ptr() ? container_type(aOther.instance_as<AbstractType>()), container_type()) {}
        ~custom_type() {}
    public:
        virtual const i_string& name() const { return iName; }
        virtual i_string& name() { return iName; }
        virtual i_string* to_string() const { if (!!iInstance) return detail::to_string<type_traits::has_saving_support<AbstractType>::value>()(*iInstance); else return new string(); }
        virtual i_custom_type* clone() const { return new custom_type(*this); }
        virtual i_custom_type& assign(const i_custom_type& aRhs)
        {
            if (aRhs.name() != name())
                throw type_mismatch();
            if (iInstance == std::nullopt)
                iInstance = ConcreteType(aRhs.instance_as<AbstractType>());
            else
                *iInstance = aRhs.instance_as<AbstractType>();
            return *this;
        }
        virtual bool operator==(const i_custom_type& aRhs) const
        {
            return instance_ptr() == aRhs.instance_ptr() || (instance_ptr() != nullptr && aRhs.instance_ptr() != nullptr && instance_as<AbstractType>() == aRhs.instance_as<AbstractType>());
        }
        virtual bool operator<(const i_custom_type& aRhs) const
        {
            return (instance_ptr() != nullptr && aRhs.instance_ptr() != nullptr && instance_as<AbstractType>() < aRhs.instance_as<AbstractType>()) || (instance_ptr() < aRhs.instance_ptr());
        }
    public:
        virtual const void* instance_ptr() const { return iInstance != std::nullopt ? static_cast<const AbstractType*>(&*iInstance) : static_cast<const AbstractType*>(nullptr); }
        virtual void* instance_ptr() { return iInstance != std::nullopt ? static_cast<AbstractType*>(&*iInstance) : static_cast<AbstractType*>(nullptr); }
    private:
        string iName;
        container_type iInstance;
    };
}
